1. Field of the Invention
The present invention is related to the encoding of video streams. In particular, the present invention is directed to a high quality wavelet video codec.
2. Description of the Related Art
There is a need in the art for a way to achieve full screen real-time playback of high quality movies using a conventional desktop computer system. Although conventional methods have attempted to satisfy this need, they have been largely unsuccessful for a variety of reasons.
One conventional method for providing video playback is by transforming the video signal from the configuration domain into the frequency domain. Frequency-domain video compression is used in such standards as MPEG-2, MPEG-4, Windows Media, etc. Furthermore, most frequency-domain techniques also involve motion vectors to give further compression in the time domain by keying off of a key frame with a motion vector. Such a process makes random access to frames a time-intensive process, making it difficult to do video editing, also known as “scrubbing”, in which a user should be able to quickly advance forward and backward through the video.
An alternative conventional solution is to encode a video stream according to a standard optimized for still images, such as the JPEG standard. However, single frame encoding algorithms are not typically fast enough to be displayed at real-time rates such as 24-frames per second. In addition, because of differences from one frame to the next, artifacts such as boiling and shimmering can occur. Entities (humans, cartoons, etc.) appearing against a background such as a textured wall are particularly disposed to these effects. And, while wavelet technology with a compression-ratio goal of about 1 bit per pixel—at least for still-frame applications—has been around since the 1980s, it has achieved such ratios only for playback at insufficient quality. Wavlet compression of high-quality video has remained elusive to date.
Accordingly, there is a need for a system and method for encoding video that yields very high quality images while smoothly playing at full video speeds.